As is well known and understood, one of the major concerns of designers of antenna system trunk transmission communications links is the elimination or reduction of external interference sources such as jamming and self-interference in a dense communications environment. Also as is well known, the beamwidth of the antenna is constrained by the allowable physical size of its aperture and most arrangements which attempt to resolve the problems of external interference do so in a relatively complex manner, often utilizing very large directional antennas or with antennas having hundreds or more elements to reduce the received beamwidth.
Mobility requirements and cost restrictions generally prevent utilizing an antenna size that provides a beamwidth of less than one degree in present state of the art transmission systems.
Accordingly, it is an object of the present invention to eliminate external interference at the receiving end of a transmission link.
Another object of the invention is to provide an interference cancelling receiving antenna system operating in a dense communications environment.
Still a further object of the invention is to provide a receiving antenna system having a relatively very narrow beamwidth for eliminating or reducing external interference from undesired signal sources.